This invention relates in general to internal combustion engines and, in particular, to an improved internal combustion engine of the rotary type.
In an effort to eliminate many of the engineering problems associated with reciprocating, piston-type internal combustion engines, a considerable amount of research and design work has recently been directed toward development of a rotary type of engine. This effort has led to the development of three different types of rotary engines, including: (1) rotary engines having a three-lobed rotor for movement around a three-lobed chamber; (2) rotary engines having special rotating abutments; and (3) rotary engines with special sliding abutments.
This invention deals primarily with a rotary engine of the rotating abutment type. This type of engine typically includes an outer housing which is comprised of a cylindrically-shaped outer wall and a pair of end walls. One end wall is attached to each end of the cylindrically-shaped outer wall to provide an annular chamber within the housing. In addition, the end walls are typically arranged to support a drive shaft which is positioned to extend through the axial center of the annular chamber defined within the outer housing. A conventional spark plug is normally mounted in the circular outer wall of the housing such that it communicates with the annular chamber. An inlet port is provided in the outer housing to introduce a mixture of air and fuel into the annular chamber, and an outlet port is provided to release exhaust products therefrom.
Engines of the above-mentioned type also include a pair of piston-forming pieces which are typically mounted onto the drive shaft adjacent to each other. Each of the piston-forming pieces is normally constructed to have a central hub and a pair of oppositely disposed pistons which extend radially outward from the central hub. The piston-forming pieces are positioned on the drive shaft such that the pistons of these pieces are alternately situated within the annular chamber and such that the pistons of each piece overlap the hub portion of the adjacent piece and extend from one end wall of the inner chamber to the other. In this way, the pistons cooperate with the cylindrically-shaped housing and opposing side walls to define four separate chambers.
In operation, the piston-forming pieces interact to simulate the characteristics of an otto cycle, i.e., intake, compression, combustion and exhaust. A detailed description of the operation of this type of rotary engine is given in U.S. Pat. No. 2,088,779, which was issued to C. C. English on Aug. 3, 1937, and in U.S. Pat. No. 3,136,030, which was issued to A. E. Ievins on June 9, 1964. Both of these patents are herein incorporated by reference.
A brief description of the operation of this type of engine, however, will be undertaken at this time to provide a better basis for understanding the significance of the present invention. The combustion cycle is started when an explosive mixture of air and gas is compressed between two adjacent pistons in proximity to the spark plug. At this time, one of the pistons is locked in a stationary position and is designated the abutting piston. The other piston is designated the driving piston and is in turn temporarily coupled with the drive shaft.
The spark plug is then fired, causing the mixture of air and gas which is compressed between the abutting and driving pistons to be ignited. The explosive force thus produced causes the driving piston to be driven away from the abutting piston in a forward direction. Since the driving piston is now coupled with the drive shaft, rotary movement of this piston is in turn imparted to the drive shaft. Movement of the drive piston also causes the exhaust products from a previous firing to be driven out of the annular chamber through the outlet port.
The piston-forming piece of which the driving piston is a component carries an opposing piston which extends radially outward from the central hub portion of this piece in a direction which is diametrically opposite to that of the drive piston. Accordingly, both of these pistons move through the annular chamber in unison. As the opposing piston moves through the chamber, it draws air and gas into the inner chamber of the engine through the inlet port. Movement of this piston toward the abutting piston also causes the mixtue of air and gas located between these two pistons to become compressed. Further movement of the opposing piston twoard the abutting piston causes the abutting piston to be moved into position to become the driving piston for the next power stroke. To properly position the abutting piston for use as the driving piston during the next power stroke, forward movement of this piston is restricted to a set distance until just prior to firing of the spark plug initiating the next power stroke.
During the latter part of the first power stroke when the opposing piston is moving the abutting piston in position to be the driving piston for the second power stroke, the piston-forming piece carrying the opposing piston becomes coupled with the drive shaft so as to receive rotary motion therefrom. Once the opposing piston assumes the position previously occupied by the abutting piston, the piston-forming piece associated with the opposing piston is disconnected from the drive shaft and the opposing piston is locked in a stationary position to form the abutting piston for the next power stroke. Thereafter, the forward restriction on the new driving piston is removed, the piston-forming piece carrying the new driving piston is coupled with the drive shaft, and the spark plug is fired to initiate the next power stroke.
Accordingly, every rotary engine of the rotating abutment type must be operable to perform several basic functions. In particular, the engine must be able to control the movement of the rotating pistons to periodically form a combustion chamber about the spark plug. In order to do this, the engine must be operable to hold the abutting piston of the chamber in a stationary position when the spark plug is fired and to restrict forward movement of the driving piston until just before firing of the spark plug. The engine must also be operable to couple the driving piston to the drive shaft upon firing of the spark plug to thereby transfer to the drive shaft the rotary motion imparted to the driving piston upon firing of the spark plug. Finally, the engine must be operable to couple the drive shaft to the piston-forming piece carrying the driving piston during the latter part of the power stroke to thereby transfer rotary motion to the piston-forming piece.
These basic functions are normally regulated by a pair of movement control mechanisms which are incorporated into the engine. An example of such a movement control mechanism is given and described in U.S. Pat. No. 2,088,779, which was issued to C. C. English on August 3, 1937. Another technique for controlling these functions is given and described in U.S. Pat. No. 3,136,303, which was issued to A. E. Ievins on June 9, 1964. As mentioned above, both of these patents are incorporated by reference herein.
These prior art control mechanisms, however, are fairly complex in design and operation. As a result, the presently known rotary engines are costly to manufacture and maintain and are unreliable at higher speeds.
It is therefore an object of the present invention to provide an improved rotary engine of the rotating abutment type which is simple in design and operation.
Another object of the present invention is to provide an improved rotary engine of the rotating abutment type which is simple and economical to construct and operate.
An additional object of the present invention is to provide an improved rotary engine of the rotating abutment type which operates in a reliable manner at both high and low speeds.
Another object of the present invention is to provide an improved rotary engine of the rotating abutment type which may be quickly and easily repaired.
It is a further object of the present invention to provide an improved rotary engine of the rotating abutment type which utilizes a unique movement control mechanism that greatly simplifies the design and operation of such an engine.
It is an additional object of the present invention to provide an improved rotary engine of the rotating abutment type which utilizes a unique movement control mechanism that reliably controls the movement of the engine's pistons at both high and low speeds.
Other and further objects of this invention, together with the features of novelty appurtenant thereto, will appear in the course of the following description.